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For an RV AC with 13,500 BTUs, a generator providing at least 3,000 watts is necessary to handle both the starting and running wattage effectively. If your AC is larger, such as a 15,000 BTU unit, opt for a generator with at least 4,000 watts. For setups with dual AC units or additional appliances, a generator capacity of 6,000 watts or more may be required to ensure all devices can operate simultaneously without issue.
Should you know more about how to size a generator for your RV AC, please read on.
On RV AC
RV AC units differ from home air conditioning systems in terms of size, installation, and power consumption. Typically, these are rooftop installations that cool the vehicle's interior directly. The power they require depends on their capacity, often measured in British Thermal Units(BTUs) . A higher BTU rating indicates a greater cooling capacity, which, in turn, demands more electrical power.
Types of RV ACs
RV air conditioners come in various types, each with specific power needs that influence the choice of generator. The most common types include:
- Rooftop Air Conditioners: Predominantly used in RVs, rooftop units are installed directly on the roof, providing efficient cooling from a high vantage point. They typically range from 11,000 to 15,000 BTUs. Because of their placement, they distribute air evenly throughout the vehicle, making them effective for consistent cooling in varying climates.
- Under-bench Air Conditioners: These units are installed under furniture or in storage compartments, making them ideal for smaller RVs or for those seeking a less obtrusive installation. Under-bench air conditioners usually have lower BTU ratings than rooftop models, as they are intended to cool smaller areas or serve as a secondary cooling source.
- Portable Air Conditioners: Offering the most flexibility, portable air conditioners can be moved within the RV or taken outside. They are perfect for targeted cooling or for use in smaller areas that do not require constant air conditioning. Portable units typically require less power, which can be beneficial for RVers who use smaller generators or who prioritize energy efficiency.
Larger RVs or those traveling in hotter climates might benefit from the higher BTU output of rooftop air conditioners, while those with minimal space or lower cooling demands might find under-bench or portable units more appropriate.
What Size Generator for an RV Air Conditioner?
| RV AC BTU Rating | Running Wattage | Starting Wattage | Generator Size |
|---|---|---|---|
| 9,000 BTU | 950 watts | 1,700 watts | At least 2,000 watts |
| 11,000 BTU | 1,250 watts | 2,300 watts | At least 2,500 watts |
| 13,500 BTU | 1,500 watts | 2,800 watts | At least 3,000 watts |
| 15,000 BTU | 1,800 watts | 3,500 watts | At least 4,000 watts |
| Dual 13,500 BTU | 3,000 watts (total) | 5,600 watts (total) | At least 6,000 watts |
Generators must be capable of handling the peak start-up wattage, which often exceeds the running wattage due to the initial surge required to activate the compressor and fans. Below is a detailed guide covering more BTU ratings and the generator capacities recommended for each.
Small to Medium RV AC Units
- 9,000 BTU RV AC: These smaller units are less common but ideal for compact RVs. They typically have a running wattage of about 950 watts and a starting wattage of approximately 1,700 watts. A generator with at least 2,000 watts will suffice for these air conditioners.
- 11,000 BTU RV AC: For slightly larger units, which are common in medium-sized RVs, the expected running wattage is around 1,250 watts with a starting wattage of about 2,300 watts. A generator with a capacity of at least 2,500 watts is advisable to cover the starting surge.
Large RV AC Units
- 13,500 BTU RV AC: This size is among the most popular for standard RVs. The running wattage for these AC units is approximately 1,500 watts, and the starting wattage can reach 2,800 watts. A generator of at least 3,000 watts is required to operate these air conditioners effectively.
- 15,000 BTU RV AC: For larger RVs or those needing more robust cooling, these units demand a running wattage of about 1,800 watts and a starting wattage that can approach 3,500 watts. Generators in the range of 4,000 watts are recommended to handle the increased power needs comfortably.
Very Large or Dual AC Units
Dual AC Systems: If your RV is equipped with two AC units, each at 13,500 BTU, the combined running wattage is around 3,000 watts, with a starting requirement that can spike to approximately 5,600 watts. For such setups, a generator with at least 6,000 watts will be necessary to run both air conditioners simultaneously without issue.
Note: When sizing a generator for an RV that includes operating additional appliances such as refrigerators, microwaves, or chargers, it's crucial to add these power requirements to your total calculation. For instance, if you expect to use a microwave (typically 800 watts) and a refrigerator (average 150 watts) along with a 13,500 BTU AC, you should consider a generator with a capacity of at least 4,500 watts.
Additionally, it is prudent to select a generator with a slightly higher capacity than the calculated need to avoid overloading. Generators operating near their maximum capacity can wear out more quickly and may not handle unexpected surges as effectively.
How Long Can You Run an RV AC With a Generator?
Typically, a standard portable generator with a fuel capacity of about one gallon can sustain an RV air conditioning unit of up to 13,500 BTUs for approximately 8 to 9 hours on a single tank of gasoline when running at 50% load. This runtime represents an efficient balance between power output and fuel consumption, suitable for most common RV setups.
For larger RV air conditioners, such as those rated at 15,000 BTUs, a generator with a larger fuel tank, around 3 to 4 gallons, might be necessary. Such generators can extend operational times to about 18 hours under similar load conditions, significantly reducing the frequency of refueling. This can be especially beneficial for travelers who wish to maintain cooling overnight or throughout the day without interruption.
Moreover, dual fuel generators, which can operate on both gasoline and propane, offer additional flexibility. When running on propane, these generators can extend their operating time further, depending on the size of the propane tank. A 20-pound propane tank might allow the generator to run for extended periods, which is ideal for longer stays in remote locations where gasoline might not be readily available.
In addition to conventional fuel generators, solar generators serve as a sustainable alternative, especially in sunny climates. Solar generators operate silently and without emissions, drawing energy from solar panels. The capacity to run an RV AC on solar power depends significantly on the solar generator's battery storage capacity and the amount of sunlight available. For instance, a robust solar generator equipped with high-capacity batteries and efficient solar panels might run a mid-sized RV AC unit throughout the day if the sun exposure is optimal. However, to ensure continuous operation during cloudy days or at night, additional battery storage or an alternate power source might be necessary.
Final Words
Selecting the correct generator size for your RV AC is crucial for ensuring that you have a reliable source of power for cooling during your travels. It's not only about matching the wattage requirements of your AC but also considering potential additional power needs for other appliances. With the right generator, you can enjoy your adventures without worry, staying cool and comfortable no matter where your travels take you.
